KOI-12 b
KOI-12 b is a cold gas giant orbiting KOI-12 in the constellation Cygnus. It lies about 1,303 light-years from Earth and was discovered in 2015 using the transit method.
How Big Is KOI-12 b?
KOI-12 b has a radius of 13.79 times that of Earth, or 1.23 times the radius of Jupiter. Its mass is 350 times that of Earth.
Is KOI-12 b in the Habitable Zone?
The position of KOI-12 b relative to the habitable zone of KOI-12 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on KOI-12 b — one full orbit around KOI-12 — lasts 17.9 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.154 AU — closer to its star than Mercury is to the Sun. Its orbit is highly elliptical (eccentricity 0.34), swinging dramatically closer to and farther from its star.
How Was KOI-12 b Discovered?
KOI-12 b was discovered in 2015 using the transit method, with observations from Kepler.
The transit method watches a star for the tiny, regular dip in brightness that occurs when a planet crosses in front of it. The depth and timing of these dips reveal the planet's size and orbital period.
How Far Away Is KOI-12 b?
KOI-12 b is 1,302.7 light-years (399.4 parsecs) from Earth. Light arriving here tonight left the planet about 1,303 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 22,927,520 years to make the journey.
Earth Similarity Index
The Earth Similarity Index (ESI) scores how physically similar a planet is to Earth, from 0 to 1, based on radius, density, escape velocity and surface temperature. KOI-12 b scores 0.07, ranking #4,925 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: KOI-12
KOI-12
- Mass
- 1.50 M☉
- Radius
- 1.40 R☉
The KOI-12 Planetary System
KOI-12 b is one of 2 known planets in the KOI-12 system. Its siblings:
KOI-12 b — Complete Data
| Radius | 13.787 Earth radii (1.230 Jupiter radii) |
|---|---|
| Mass | 349.61 Earth masses (1.100 Jupiter masses) |
| Orbital period | 17.86 days |
| Orbital distance | 0.154 AU |
| Eccentricity | 0.340 |
| Earth Similarity Index | 0.07 |
| Distance from Earth | 1,302.7 light-years (399.4 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2015 |
Data: NASA Exoplanet Archive, last updated 2019-11-01. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About KOI-12 b
Is KOI-12 b habitable?
KOI-12 b is not known to orbit within the habitable zone of KOI-12, and as a cold gas giant it is an unlikely candidate for life as we know it.
How far away is KOI-12 b?
KOI-12 b is about 1,303 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 22,927,520 years to get there.
How big is KOI-12 b compared to Earth?
KOI-12 b has 13.79 times the radius of Earth and about 350 times its mass.
How long is a year on KOI-12 b?
One orbit around KOI-12 takes 17.9 Earth days — short enough that 20 of its years would fit into one Earth year.
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